Has anyone ever tuned there guitar down a whole step while leaving the bass up in standard? Or maybe leave the guitar up and tune the bass down? If this doesn't sound good can someone recommend some tunings similar to this? thanks

I don't see how it would be an issue. If you're playing (for example) an E5 chord on a guitar tuned to Drop C, it doesn't matter if the bass is tuned to E standard or Drop C or Drop A. You should be able to recognize what notes are being played, regardless of where they're played on the guitar/bass.

There's no reason you couldn't, but it's pointless. Why would you want to add a step of range to one instrument, and not give the other the ability to reach it? That's the reason the guitar and bass are generally tuned the same, with the occasional exception of the bassist having an extra low string while the guitar doesn't (5 string bass with 6 string guitar).